Field of the Invention
The present invention relates to an information processing apparatus including a switching unit for switching between the supply and the cutoff of power to the information processing apparatus and a method for controlling the information processing apparatus
Description of the Related Art
Up until now, to realize saving power of an apparatus, there has been known an image processing apparatus such as a copying machine and a printer including an automatic-OFF drive circuit for automatically turning off a power switch if the apparatus is not used for a certain period of time.
Japanese Patent Application Laid-Open No. 2008-142942 discusses an apparatus executing automatic power-OFF function in which a power switch is equipped with a mechanical relay, and when the power switch is turned on, the relay is driven by signal control from the outside to turn off the power switch.
If the automatic power-OFF function is executed, the power switch is thrown to a OFF side by the mechanical relay to shut down the power source of an image forming apparatus from an alternating current (AC) power input unit. The control unit of the image forming apparatus returns the image forming apparatus to a normal mode even in a power saving mode, so that power is supplied to a large number of portions to operate the apparatus.
Cutting off the power from the control unit during its operation may cause problems of the apparatus such as disappearance of data and failure in driving components. In order to avoid such problems of the apparatus, the automatic power-OFF function needs to be executed after the shutdown preparation control of the control unit is executed and time elapses to such an extent that the apparatus is not affected even if the power is shut down.
If the drive of the mechanical relay using a driving signal fails for some reason, the power of the apparatus is not turned off even if the automatic power-OFF function is executed. For example, the above phenomenon is caused in a case where a user happens to exert force to a power switch when the mechanical relay is driven by a driving signal.
Thus, if the turn off of the power switch cannot be made, the power switch of the apparatus is still turned on, but the control unit already completes the shutdown preparation control, so that a freezing state where the apparatus cannot receive operation from the user is continued.
In this state, the control unit is in a shutdown ready state, so that neither the control unit can issue a notification of error nor the user can make determination, which may inhibit the apparatus from being used.
Similarly, if the driving unit of the mechanical relay, a wiring for a driving signal, and the power switch itself fail, the control unit executing the automatic power-OFF function cannot turn off the power source of the apparatus, bringing the apparatus into a freezing state.
Turning on and off the power switch in the above state sometimes can return the apparatus to a normal mode, however, if the automatic power-OFF function is executed again from the power saving mode, the apparatus is brought into the freezing state. If the apparatus is brought into the freezing state, the shutdown preparation control is completed irrespective of a state where the apparatus is supplied with power, so that the apparatus cannot receive any operation from the user, which consumes useless power.
The freezing state can be prevented from occurring again unless the automatic power-OFF function is used, however, the control unit completes the shutdown control, so that the control unit cannot execute a process where the user is notified of the failure using an error massage. For this reason, the user cannot determine the state, so that the apparatus is prevented from being used.